Container gardening or planting has been well known in the gardening arts for literally centuries, with surviving examples being known from, for example, the Roman, Greek and Sumerian periods. Stated simply, container gardening is the growing of plants in a body of soil contained in a container which may, for example, be pottery, terra cotta, cement, stone, wood, plastic, and so on and which may be located either indoors or outdoors. The sole requirements are that the containers be capable of containing and supporting the soil or other growing medium and that the containers be capable of retaining the desired degree or content of moisture for a sufficient period, which will depend on the requirements of the plants growing within the container and the growing environment and conditions.
Container gardening is advantageous in may instances because it allows more control over the growing process and, for example, allows plants to be grown in circumstances, such as indoors or on patios or in other places where in-ground methods are not practical or convenient, and allows a more efficient use of the available space because the containers can often be stacked vertically one on top of the other.
A recurring problem in container gardening, however, is watering the plants in order to maintain the necessary or desired degree of moisture in the growing medium which may be, for example, soil, a man-made medium or a mixture or combination thereof. That is, the volume of growing medium in a container is much smaller, on a per plant basis, than when the plant is grown in the ground so that the plant will generally consume the moisture in the growing medium at a much faster rate than the same plant would if planted in the ground. In addition, a container, particularly one in a stacked or a nested array of containers, is less efficient at capturing moisture, e.g., rain or water from a water pail or garden hose, than is the ground. Also, the moisture will often escape from the growing medium within a container at a much faster rate than the moisture will from the ground because of the proportionally much greater ratio of exposed surface area to volume of the growing medium in a container as compared to, for example, the soil in a field or a planting bed.
While there are methods addressing at least some of these problems, they have generally proven unsatisfactory. For example, the loss of moisture from a container through the container sides or bottom may be reduced by making the container waterproof. This solution for moisture retention, however, introduces or greatly increases an excessive amount of water in the growing medium and possible “drowning” and/or rotting of the root system of the plant.
Yet another approach to certain of the problems associated with container gardening is various forms of an automatic watering system or mechanism. Such systems or mechanisms may include, for example, various irrigation systems with various forms of piping and timer controlled valves connected to a water source, or valves controlled by one or more electrical moisture sensors. Such systems or mechanisms, however, are generally expensive and prone to failure and often require a separate sub-system for each container layer when the containers are stacked because of the well known tendency for water or other liquids to flow or migrate downhill, due to gravity, often to a location or area where the water or liquid is not wanted or required.
One variation on the known watering method employs one or more water conductive elements, such as capillary tubing or material having capillary properties. The capillary tubing or material draws water from a reservoir and delivers the water to the desired location in the growing medium. This method provides a solution to some of the above discussed problems in that these methods deliver the water generally on demand and when needed and do not require any moving parts, such as electrical power or sensors. That is, typically one end of the capillary element is embedded in the growing medium at a desired watering point or location while the opposite end the capillary element is placed in a source of water. Then, the capillary element will “sense” the difference kin moisture, between the growing medium and the water source, and when the growing medium becomes too dry, will “draw” or “pump” water from the water source to the growing medium, via capillary action of the capillary element, at a rate determined by the relative moisture differential across the capillary element.
The capillary method of watering various growing mediums in various circumstances has been so successful that it is often used to irrigate fields and planting beds and to control the delivery of moisture to seed germination beds, as well as to irrigate plants in growing containers. Notwithstanding these improvements, even the currently known capillary systems present problems in certain circumstances. For example, when a plurality of containers are stacked vertically, it is generally necessary to provide a separate reservoir and capillary system for each stacked layer and to isolate effectively each stack layer from the other stacked layers, whether or not each layer is constructed as a separate container unit or constructed as a single, integral unit. Again, this problem arises because of the tendency of water to flow downhill, due to gravity, which could otherwise result in the water in the upper layers, containers, reservoirs and capillary systems leaking or flowing downward into the lower layers, containers, reservoirs and capillary systems with a resulting lack of moisture for the upper stacked layers, containers, reservoirs and capillary systems and excess water, and possibly an overflow of water, in the lower stacked layers, containers, reservoirs and capillary systems.
The construction of each container layer, as a separate isolated and self-contained unit, also introduces additional problems. For example, the typical need to provide a separate reservoir and capillary system for each stack layer and to effectively isolate each stack lever from lower stack layer increases the complexity, weight and cost of the stackable containers. In addition, and as part of the added complexity, it is typically necessary to provide a separate access to an associated reservoir for each layer of a stacked array of containers due to a number of reasons. For example, the reservoirs are typically isolated from one another to avoid unwanted leaks and overflow when filling, which automatically results in a requirement for some form of a separate access to each reservoir. This requirement, in turn, imposes notable constraints on the design of the container layers, which typically includes an inconvenience in accessing each reservoir and difficulty in seeing the current water level of each reservoir which, in turn, may result in either under filling of a reservoir, and thus insufficient watering, or overfilling of a reservoir with a consequent mess or problem associated with water overflowing from or leaking out of the portable planting system.